Water-lifting and aeration system improves water quality of drinking water reservoirs: Biological mechanism and field application

Reservoirs have been served as the major source of drinking water for dozens of years. The water quality safety of large and medium reservoirs increasingly becomes the focus of public concern. Field test has proved that water-lifting and aeration system (WLAS) is a piece of ef-fective equipment for in situ control and improvement of water quality. However, its intrin-sic bioremediation mechanism, especially for nitrogen removal, still lacks in-depth investi-gation. Hence, the dynamic changes in water quality parameters, carbon source metabolism, species compositions and co-occurrence patterns of microbial communities were systemat-ically studied in Jinpen Reservoir within a whole WLAS running cycle. The WLAS operation could efficiently reduce organic carbon (19.77%), nitrogen (21.55%) and phosphorus (65.60%), respectively. Biolog analysis revealed that the microbial metabolic capacities were enhanced via WLAS operation, especially in bottom water. High-throughput sequencing demonstrated that WLAS operation altered the diversity and distributions of microbial communities in the source water. The most dominant genus accountable for aerobic denitrification was iden-tified as Dechloromonas. Furthermore, network analysis revealed that microorganisms inter-acted more closely through WLAS operation. Oxidation-reduction potential (ORP) and total nitrogen (TN) were regarded as the two main physicochemical parameters influencing mi-crobial community structures, as confirmed by redundancy analysis (RDA) and Mantel test. Overall, the results will provide a scientific basis and an effective way for strengthening the in-situ bioremediation of micro-polluted source water.(c) 2022 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.